The present invention relates to a needle for medical use comprising an easily bendable cannula which has a small diameter and a thin wall. The needle for medical use of the present invention is suitable as a dental needle used for local anesthesia in dental treatment or a needle used for delivery of insulin.
In dental treatment, dental needles have generally been used to inject an anesthetic agent into a dental root. In this case, it is general practice to bend a cannula from the root thereof to a suitable angle just before use of needle since the needle cannot be guided to a site of injection as it is because of a small oral cavity prevent.
However, such a needle involves a danger of causing breakage of the cannula at the time of sticking the needle into the dental root. Further, the above bending operation is often applied two or more times to the needle used for the identical patient, so that the cannula breaks at the root during the bending operation of the needle before the medical treatment.
On the other hand, needles for delivery of insulin comprise a cannula which has a small diameter and a thin wall. For this reason, the needles have such a problem that the cannulae are often broken in use (i.e., at the time of puncture or removal of the needle) because of a matter of procedure, probably, incorrect puncture of the needle.
In view of the above circumstances, the present invention has been made and an object of the invention is to provide a needle for medical use which is free from breakage of the cannula even if subjected to repeated bending operation or puncture into root of teeth in use. Another object of the present invention is to provide a needle for medical use, which is free from breakage of cannula owing to a matter of procedure.